UNESCO-IHE Institute for Water Education,Bangladesh University of Engineering and Technology,Tube Barrier, Green Soil Bags,Flexbase, Urban Wetlands

Protecting crops in times of flooding

CORE is a NWO-funded research project focusing on community-based development and implementation of small-scale technical innovations that alleviate immediate flood-related nuisance in urban Bangladesh. The project is led by UNESCO-IHE Flood Resilience Group, in collaboration with the Bangladesh University of Engineering and Technology.

Field Factors' contribution to the project consists of the development of a flood-proof seedling bed prototype, which will be implemented at the CORE’s experimental learning space in Bangladesh. The prototype demonstrates a scalable system that integrates level-controlled drainage and recirculation of drain water to optimise water usage, while protecting crops from flooding. It provides farmers with a sustainable solution to regulate the irrigation of young crops in an open field in a targeted manner.

The system will be designed adapted to the hydrological, environmental, social and economic conditions of urban Bangladesh. The implementation of the system aims to:

Contribute to a small-scale, community based flood-proof urban environment;

Make maximum use of local available materials, resources and manufacturing facilities;

Stimulate local adoption, ownership and replication of the solution.

__Identify

Understanding the users and their needs.

Through field trips and workshops with local stakeholders and end-users, we have gathered insights into the users needs and the local context. For the Bangladeshi, flooded streets or houses do not represent a major problem, but the loss of crops is a major setback due to the scarcity and price hike of new saplings. In the dry season water becomes scarce: salty seawater gets the chance to push back the freshwater in the rivers. This makes the surface water brackish and unsuitable for use, damaging crops.

These insights provided us with a design brief:

how to create a water regulated environment for farmers to grow young crops all year round.

__Design

Based on our knowledge of retention and bio-filtration systems, we designed a flood-proof seedling bed with level-controlled drainage and re-circulation of drain water. The seedling bed is protected from flooding by a closed system in a ring structure. Beneath the seedling bed, a layer of gravel is applied where the drained water can be stored. In this gravel layer, drainage pipes are placed, allowing controlled drainage to discharge the excess of water.

During the monsoon, the water level within the system may rise, but the appropriate water level can be maintained by raising or lowering the outlet. In the dry season the same drain works the other way around: providing the crops with water stored in the gravel layer.

__Develop

Currently, the design of the system is being tested through a full-scale prototype and optimised to build our demonstrator in Siranjganj, Bangladesh.